Our Autism Center of Excellence (ACE) aims to discover the mechanisms related to early brain[unreadable] overgrowth in autism and to define specific behavioral and biological factors associated with infants at-risk[unreadable] for the disorder. These goals can only be achieved if autism is studied prospectively. Currently, the only[unreadable] prospective strategy in use is the baby-sibling design. Unfortunately, the baby-sib approach is weighed[unreadable] down by heavy research costs, long time frames to identify and follow cases, and only represents autism as[unreadable] it occurs in multiplex families.[unreadable] The Clinical Phenotype: Recruitment and Assessment Core (CPRAC) will implement a different strategy,[unreadable] called the 1-Year Well-Baby Check-Up Approach, to identify and study infants at risk for an ASD[unreadable] prospectively. As shown in the preliminary results section, this approach has the potential to identify at-risk[unreadable] cases quickly, and for a fraction of the cost of baby-sib research. Importantly, this unbiased approach will[unreadable] identify ASD cases from singleton and multiplex families alike, and as such may more realistically represent[unreadable] the population of autism. This method will allow infants at-risk for an ASD as well as those at-risk for a[unreadable] developmental disorder (DD) to participate in MRI (Project 1), fMRI (Project 2) and genetic research studies[unreadable] (Projects 3 and 4) beginning at 12-months in age. The CPRAC will also recruit, using the same approach,[unreadable] age, gender and ethnicity-matched typical controls. Thus, the CPRAC will recruit a total of 3 study groups:[unreadable] at-risk ASD, at-risk DD, and typical.[unreadable] The CPRAC will also thoroughly characterize each study infant using standardized clinical and[unreadable] experimental measures in the general areas of social, cognitive, language, and exploration behavior.[unreadable] Infants will also receive a thorough physical and neurological examination and have blood samples collected[unreadable] through CPRAC services. The CPRAC will follow infants longitudinally and collect selected study data every[unreadable] 6 months until each participant turns three years old.[unreadable] CPRAC investigators will implement quality control of assessments and adhere to all research subject[unreadable] protection guidelines including HIPAA.[unreadable] In summary, the CPRAC will be responsible for: 1) identification and recruitment of 12-month old infants;[unreadable] 2) diagnostic and psychometric evaluations of study infants every 6 months 3) coordination of each infant's[unreadable] participation in Projects 1-4; 4) final diagnoses when each participant turns three. The CPRAC will also be[unreadable] responsible for informed consent and ensuring compliance with current clinical and research standards and[unreadable] guidelines, including HIPAA. The CPRAC will also work closely with investigators on each of the projects, as[unreadable] well as the other Cores.